Another Epic Battle Plays Out in Virginia : Campaign: The North vs. Robb slugfest for the U.S. Senate nears a climax. A desperate air signifies the stakes for the Democratic, Republican parties.

MANASSAS, Va. — The man who may be only days away from becoming Virginia's next senator lopes onto the train station platform, one hand protectively cradling a foam coffee cup while the other reaches out in greeting to 100 or so well-wishers waiting in the chilly morning air to meet him.

"Good mornin', folks," he says, flashing the well-known gap-toothed smile that makes him look like he is still in the process of shedding his baby teeth. "I'm Oliver North and I'd sure appreciate your vote."

"You got it, Ollie!" shouts a heavyset man in the back of the crowd. "God bless you, Senator," affirms a woman's voice from somewhere in the middle of the gathering.

Wait a minute. Senator Oliver L. North? The cloak-and-dagger colonel who ran the illegal Iran-Contra operation that became the worst scandal of the Ronald Reagan Administration, who was convicted of shredding classified documents, accepting illegal gratuities and misleading Congress? The man who has been denounced by Nancy Reagan as a congenital liar? Can this same man really be on the verge of winning a seat in the institution he stonewalled only five years ago in the Iran-Contra investigation?

"It sure looks that way," says Mark Rozell, a political scientist at Mary Washington College in Fredricksburg, Va. "North has run a very smooth and energetic campaign, whereas (incumbent Democratic Sen. Charles S.) Robb's campaign has been lackadaisical and out of focus from the start."

Now, as it enters its final week with both men in a virtual dead heat in the polls, the most controversial campaign in the nation is assuming an aura of desperation that underscores its significance for both parties as the candidates escalate their bitter attacks on one another.

The issues have been largely obscured by the personalities and their respective liabilities but, underneath the mantle of meanness, two titanic struggles are being waged--one for a seat that is crucial to the Democrats' effort to retain control of the Senate next year and the other for the soul of the Republican Party in the state that bred so many of the nation's Founding Fathers.

When Republican North formally announced his Senate candidacy nine months ago, few observers expected that he would get this far. But it is now clear that the political establishments of both parties underestimated both North's appeal and his formidable skills as a fund-raiser and campaigner.

North has waged "the best campaign that money can buy," conceded Robb strategist Burt Rohrer, who noted that North has raised more money--$17.6 million--than any other Senate candidate this year, most of it from out of state. Only multimillionaire Rep. Mike Huffington (R-Santa Barbara) has spent more--$28 million--but nearly all of that has been his own money. Robb, by contrast, has raised $4.5 million.

"North has all the money in the world and he's used it to capitalize on that anti-incumbent, anti-Washington and basically anti-everything mood that's out there this year," Rohrer said. "The only thing he doesn't have, in spite of all this, is the lead."

Rohrer said that Robb is encouraged by new polls suggesting that he finally may be edging ahead of North, who committed several verbal gaffes in the closing days of the campaign and appears to have been hurt by Nancy Reagan's stinging denunciation of him last week as someone who made "false statements" about the Iran-Contra scandal and who still has "a great deal of trouble separating fact from fantasy."

But Robb, whose campaign has become a lightning rod for many Virginians' strong sentiment against President Clinton, has not completely erased his own negatives that stem from an alleged extramarital liaison with a former beauty queen and a long-running and only recently repaired feud with former Gov. L. Douglas Wilder, the nation's first elected black governor. He has also been hurt by the fact that some of the anti-North support he counted on receiving is being siphoned away by Republican J. Marshall Coleman, who is running as an independent.

As a result, most experts rate the race as a tossup, a situation that they say inherently favors North. "Show me even numbers and I'd say North is in the driver's seat," said Rozell. "His supporters are much more fervent and motivated than Robb's and they're going to turn out in large numbers on Election Day."

"If we go into this thing tied, our people are all going to turn out," agreed John Atkinson, a North campaign aide.

A charismatic campaigner, North has proven himself particularly adept at surfing the wave of anti-incumbency fervor sweeping over Virginia with at least as much force as it is in other parts of the country.